Numerous prior art teachings deal with surface preparation of an aluminum member prior to adhesive bonding, as by grit blasting or acid etching, to thereby enhance bonding adhesion.
For example, an aluminum-plastic laminate has been formed by roughening the surfaces of a pair of aluminum sheets, subsequently etching these surfaces with a sulfochromate solution, and thereafter bonding the treated aluminum surfaces together, under heat and pressure, by inserting a thermoplastic layer therebetween.
Another method improves adhesive bonding of aluminum, or its alloys, to organic adhesives by first treating the aluminum surface with a sulfochromate solution, and then treating the surface with a reducing solution.
Yet another method enhances adhesion to aluminum by providing a layer of liquid adhesive containing a finely divided solid abrasive, followed by movement to abrade the confronting surfaces, and then curing the adhesive to bond these surfaces together.